Project Data -Wisconsin Dairy Farms

Located in Rice Lake, WI, Norswiss Farms is a 1,100 cow dairy farm operating an anaerobic digester. The system is driven by a Jenbacher JGS316 GS-BL biogas engine with JW/IC heat recovery to maintain the temperature of the digester tank. The system operates 24/7 and exports all of the generated electricity to the grid. This system will annually generate over 6,500,000 kWh. The project has an annual emission reduction of over 20,000 Metric Tons C02e

Both the biogas flow from the digester and the airflow in the gas scrubbing process are measured. These two gas streams are added together in order to correctly calculate the methane generated. The project produces a 65% reduction in Biochemical Oxygen Demand (BOD’s) and 40% reduction of total solids.

The Wisconsin dairies are not required to reduce their carbon emissions. The motivation for this project was strictly voluntary. The sale of carbon offsets generates an additional revenue which makes these projects profitable; in all three projects the sales of the carbon offsets keeps the project from operating at a loss.

In addition to methane emissions reductions, this project includes the following additional benefits:

The digester facilities have the ability to process a variety of by products other than manure for improved energy output.

Digested solids can be used to bed cows or for gardens or landscaping.